The present invention relates to an electric conduction printer which electrically transmits printing patterns to electrically conductive printing mediums such as printing forms and printing ribbons from a printing head by feeding current to a printing head having a plurality of pattern electrodes corresponding to printing pixels composed of dots.
An electrically conductive printing head which performs so-called electroconductive printing, in which printing is directly conducted onto the printing form by electroconductive action or by transfer from a printing ribbon has a disadvantage in that it can be susceptible to wear and damage because as the electrode feeding current travels its tip is being pressed onto the electrically resistant electroconductive printing form or ribbon. Thus, in order to prevent this, the electrode has conventionally been formed of hard, low resistant special metals which exhibit excellent heat-resistance and resistance to abrasion and wear. However, an electroconductive printing head having electrodes made of such metals has had the following problems which should be thoroughly eliminated.
(1) Hard metals having excellent abrasive resistance and heat-resistance have generaly been difficult to process, and it has been difficult to attain a high density of pixels on the head and to cope with the multiplication of the electrodes.
(2) Moreover, when the electrodes at the used tips are changed, it is wasteful if the drive feeding current to them is also changed, while if only the electrodes are changed independently of the drive it was necessary to finely align the drive portion and the electrodes during setting, and this work was extremely difficult. Such problems cannot be overlooked, particularly in case the head provided with a multiplicity of the electrodes on the head of a shuttle or line printer.